writable

Java序列化机制将对象装换为连续的byte数据, 这些数据可以在以后还原(反序列化)成原来的对象 Java中, 要想一个类的实例可被序列化, 该类须实现Serializable接口. Serializable接口是一个标志, 没有任何方法, 其定义如下 public interface Serializable { } 定义一个类Block1, 该类实现了Serializable接口 class Block1 implements Serializable { private int one = 1; private int two = 2; private int three = 3; @Override public String toString() { return "Block1 [one=" + one + ", two=" + two + ", three=" + three + "]"; } } 定义一个类JavaSerializeTest, 测试Java序列化机制 public class JavaSerializeTest { public static void main(String[] args) throws IOException, ClassNotFoundException { Block1 block = new Block1();

本人博客开始迁移，博客整个架构自己搭建及编码 http://www.cookqq.com/listBlog.action writeable接口对java基本类型提供了封装，short和char除外。所有的封装包含get()和set()两个方法用于读取和设置值。 Writable的Java基本类封装 Java基本类型 Writable使用序列化大小（字节） 布尔型 BooleanWritable 1 字节型 ByteWritable 1 整型 IntWritable 4 整型 VIntWritable 1-5 浮点型 FloatWritable 4 长整型 LongWritable 8 长整型 VLongWritable 1-9 双精度浮点型DoubleWritable 8 Text类型对应java的string 现在看一下IntWritable的源码 /** * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership.

To be simple, we have two similar functions: void f1() { printf("%d", 123); } void f2() { printf("%d", 124); } Now we call f1 in main and it prints 123. When it is compiled, the disassembly of f1 may be like: 08048424 <f1>: 8048424: 55 push %ebp 8048425: 89 e5 mov %esp,%ebp 8048427: 83 ec 18 sub $0x18,%esp 804842a: b8 40 86 04 08 mov $0x8048640,%eax 804842f: c7 44 24 04 7b 00 00 movl $0x7b,0x4(%esp) 8048436: 00 8048437: 89 04 24 mov %eax,(%esp) 804843a: e8 05 ff ff ff call 8048344 <printf@plt> 804843f: c9 leave 8048440: c3 ret The machine code of f2 is similar to the f1's. Now I want to

I have spring web application. I have defined the controller bean which takes the bean of service as property. Also service bean takes the Dao. Dao is tested and working fine. Now the problem with service. Actually i'd make sure about the setters there ! so what is the problem ? Controller Bean : <bean id="listTypeController" class="me.web.servlet.controller.ListTypeController"> <property name="typeService" ref="typeService" /> </bean> Service Bean : <bean id="typeService"class="me.general.service.impl.TypeServiceImpl"> <property name="genericDao" ref="genericDao" /> <property name="typeDao"

It seems to me that a org.apache.hadoop.io.serializer.Serialization could be written to serialize the java types directly in the same format that the wrapper classes serialize the type into. That way the Mappers and Reducers don't have to deal with the wrapper classes. Chris White There is nothing stopping you changing the serialization to use a different mechanism such as java Serializable interface or something like thrift, protocol buffers etc. In fact, Hadoop comes with an (experimental) Serialization implementation for Java Serializable objects - just configure the serialization factory

I am having problems with a picture uploading script. I know there are hundreds of the same questions, but I haven't found the one that would be work for me. $upload_dir = "images/postcards/"; chmod($upload_dir, 777); if (is_writable($upload_dir)) { echo 'The file is writable'; } else { echo 'The file is not writable'; } This always returns that the file is "not writable" I tried setting chmod to 0777 and -rwxrwxrwx . But result was always the same. Any Ideas? The directory must be owned by the user invoking the script (typically www-data , apache or httpd if you're running the script in a